Electron discharge device



Nov. 1, 1932. R. F. BEERS 1,886,150

ELECTRON DISCHARGE DEVICE Filed Aug. 15, 1928 INVENTOR Patented Nov. 1, 1932 ROLAND F. BEEJRS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO ,RAYTHEON, INC., 03? CAMBRIDGE, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS ELECTRON DISCHARGE DEVICE Application filed Angust'15, 1928. Serial No. 299,645.

My invention relates to electron discharge devices and particularly to a device wherein a plurality of electrodes are suitably supported for cooperative action. Rectifiers of the 5 gaseous conduction type in which spaced electrodes operate to rectify currents have usually been half wave or full wave type. If of the latter type, the tube usually had one cathode and two anodes. It has been found,

however, that in cases where a smooth, rectito obtain a smooth current.

fied current was desired that a multi-phase source of electricity was much more desirable. Due to the smaller phase angle between the impulses, less filtering equipment is necessary In order torectity both waves of two phase current, it is possible to use two separate rectifiers. How ever, this procedure is undesirable.

It has been found that the discharge between the common electrode, usually the cathode, and an anode, is initiated much more easily if at the same time there is a discharge between the cathode and an adjacent anode. This is probably due to ionized particles wandering into the region where a discharge is to be initiated. In the ordinary full wave rectifier, one discharge starts after the other has finished. It is obvious that in a tube with more than one phase of supplied current that there will always be a discharge between two electrodes and at certain portions of the cycle there will be simultaneous discharges at two anodes. By providing a rectifier of this type with a plurality of anodes for multi-phase rectification, it is possible to greatly reduce the drop across the rectifier, thus-allowing a greater useful output potential and also to have a greater current pass through the tube.

An object of my invention, therefore, is to devise a tube in which multi-phase currents may be rectified. Another object is to devise a suitable supporting structure whereby the elements of the tube will be firmly maintained in proper relation to each other.

A further object of my invention is to device a supporting structure upon which a plurality of electrodes may be supported. To support electrodes in a press, it is customary to dispose supporting members, such as wires or rods, in the press, some or all of the I supporting members, in such a press,

wires or rods being suitably connected to lead wires. The lead wires and supporting members are usually in one plane forming a row of closely spaced members. This is objecttionable for the reason that wires which car heavy currents through the seal, and therefore become heated, are close to wires which, as a rule, are at a high potential but do not carry very heavy currents. In such cases, the glass at the seal becomes heated and more conducting than when cold, causing electrolysis at the seal and consequent destruction of the tube. Furthermore, from a manufacturing point of view, it is diificult to dispose the wires in such close relationship to each other and have a suflicient amount of glass around each wire for mechanical support. Then the are very often bent in order to reach the desired electrode. This detracts from the rigidity of the entire assembly.

In some instances, certain of the supports have been scaled into the base of the press in order to obtain a suflicient spacing. This is undesirable for the reason that in such a case the glass is usually not pressed around the wire and a faulty seal is apt to occur.

By my improved press, I am enabled to obtain adequate spacing between supporting members. This is advantageous for mechanical reason because of more glass to support each member. For electrical reasons, this press is advantageous in that there is greater distance between any two supports. My press is adapted for cheap and efficient production by standard machines which need only be slightly changed. Each wire in the press is anchored in glass which has been pressed together so that a perfect seal is obtained in each case. Preferably my press is characterized by the fact that at least one supporting member is disposed in an intermediate portion of the cross section of the press while other members are arranged so that they are at the corners of a regular two dimensional geometrical figure. The supporting members or lead wires are substantially parallel for at least a portion of two outer adjacent supports or leads are at angles with each other, all of said angles being equal. In the case of four symmetrisally arranged supports as illustrated in the drawing, a rectangle would be formed at the structure. Furthermore, long leakage paths are provided by having the intermediate portions of the press below the level of the outer portions.

Referring to the drawing, Figure 1 is a sectional view of the tube.

Fi re 2 is a plan view. Within a suitable receptacle 1, such as a glass tube, is reentrant portion 2, forming the base of press 3 of glass or similar material.

This press iscompo sed of one centraldepending rtion 4 and four upstanding symmetrica y arranged portions 5. Depending portion 4 is centrally disposed with respect to the entire press while upstanding porao tions 5 are disposed around the vertical axis which terminates in a cathode lead 7. This of the press. Each upstanding portion 5 i forms a separate tubular member through which proper lead wires mayibe sealed.

In depending portion 4 is sealed a wire 6 cathode is an elongated cylindrical inember nf any suitable material such as graphite, carbon, iron, nickel, molybdenum, or any;

other suitable material. Through each of upstanding portions 5 run wires sealed therein and terminating in cylindrical anodes 9. These anodes may be terial as above named or any other refractory material, such as tungsten or molybdeuum. WThe anodes are symmetricaliy disthrough posed around cathode 7 and as shown, have po their top ends substantially in one plane.

Upstanding portions 5 terminate in tubular members 10 in which are suitable insulators 11 of lava or the like. These insulators are suitably arranged so that there is a shoulder presented upon which each of the insulators seats itselfi: upon glass tubes 10. The insulators are channeled so that the anodes go them. The inner portions of the insulators where the anodes emerge therefrom, are cut out so that two annular regions 12 and 13 are produced. A plate 14, suitably bored, restsaaround the anodes and cathode. This pgate may be of any suitable metal such as nic el or the like. The edges of the plate at regions 12 around the anodes are turned down to cover the edges of insulators 11, while around cathode 7 is a metal member 15 firmly connecting the plate and the cathode.

of any suitable ma- The outer edge 16 of plate 14 is turned down and supports a dome-like member 17, which covers the entire region of discharge. Mem- .bers 17 and 14 may be suitably welded at their meeting edges wherever desired.

The tube is exhausted and freed of'occluded gases in accordance with usual practice and filled with one or more rare gases to a pressure of 1 cm. of mercury. In order tn reduce the drop across the terminals of the tube, the

vapor of an alkaline earth or alkali metal may be introduced in well known manner if desired L Annular regions 12 and 13 surrounding the anodes are of the ordergof the mean free path oi the gas particles in the tube. These re- 10118 not only provide short path insulation between cathode and anodes but also protect the edges of the insulator from bombardment. iBy thus disposing the anodessyrmnetrically with res t to the cathode, the losses across the cat ode and each anode are rendered substantially equali Furthermore, the syrfnmetry of the electrode arrangement is such that-ionization from one region of dis charge will readily start a discharge in an adjacent region. In useIthe electrodes will be so connected that a discharge preferably travels around in a circle.

Although I have shewn four grouped around one cathode, it is perfectly obvious that; this number may be increased if desirable. Such increase in number of anodes will result in a corresponding increase in the number of supporting portions of the stem structuife.

I- claim:

' 1. An electron discharge device comprising a hermetically sealed container having a reentrant stem, a plurality of upstanding portions formed on said stem, said projections lying in a plurality of planes, a plurality of electrodes, each of said projections supporting one of said electrodes and an additional electrode, said additional electrode being suprted by and mechanically interconnecting said pro ections, whereby a rigid'three-di' mensionalsupport is afiorded for all of said electrodes and for said projections.

2. An electron discharge device comprising a hermetically sealed container having a reentrant stem, a plurality of tubular -pro ections formed on said stem, a plurality of electrodes, each of said tubular projections supporting one of said electrodes, an additional electrode, said additional electrode being supperted by and mechanically interconnecting said projections, whereby a rigid three-dimensional support is afforded for all of said electrodes and for said projections.

In testimony whereof, I have signed my name to this specification.

ROLAND F. BEERS.

anodes 

